Fix lighting of the wield mesh (minetest#12341)

* Assign node light to player before final color blend.
  Fixes day/night lightbank ratio for wield meshes
* Update wield mesh light when changing mesh

src/client/camera.cpp

@@ -47,7 +47,8 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 
 Camera::Camera(MapDrawControl &draw_control, Client *client, RenderingEngine *rendering_engine):
  m_draw_control(draw_control),
- m_client(client)
+ m_client(client),
+ m_player_light_color(0xFFFFFFFF)
 {
  auto smgr = rendering_engine->get_scene_manager();
  // note: making the camera node a child of the player node
@@ -153,8 +154,10 @@ void Camera::step(f32 dtime)
  bool was_under_zero = m_wield_change_timer < 0;
  m_wield_change_timer = MYMIN(m_wield_change_timer + dtime, 0.125);
 
- if (m_wield_change_timer >= 0 && was_under_zero)
+ if (m_wield_change_timer >= 0 && was_under_zero) {
  m_wieldnode->setItem(m_wield_item_next, m_client);
+ m_wieldnode->setNodeLightColor(m_player_light_color);
+ }
 
  if (m_view_bobbing_state != 0)
  {
@@ -555,7 +558,8 @@ void Camera::update(LocalPlayer* player, f32 frametime, f32 tool_reload_ratio)
  m_wieldnode->setPosition(wield_position);
  m_wieldnode->setRotation(wield_rotation);
 
- m_wieldnode->setNodeLightColor(player->light_color);
+ m_player_light_color = player->light_color;
+ m_wieldnode->setNodeLightColor(m_player_light_color);
 
  // Set render distance
  updateViewingRange();

src/client/camera.h

@@ -264,4 +264,7 @@ class Camera
 
  std::list<Nametag *> m_nametags;
  bool m_show_nametag_backgrounds;
+
+ // Last known light color of the player
+ video::SColor m_player_light_color;
 };

src/client/clientenvironment.cpp

@@ -305,6 +305,7 @@ void ClientEnvironment::step(float dtime)
  node_at_lplayer = m_map->getNode(p);
 
  u16 light = getInteriorLight(node_at_lplayer, 0, m_client->ndef());
+ lplayer->light_color = encode_light(light, 0); // this transfers light.alpha
  final_color_blend(&lplayer->light_color, light, day_night_ratio);
  }